FLT3 and acute myeloid leukemia: The inhibitors were observed to kill primary human AML cells having a high (>90) per cent of blasts and expressing either wt FLT3 or oncogenic FLT3 in a concentration‐dependent fashion and to a greater extent than PBMCs from a normal donor, and with higher potency than PRT062607, used as a negative control because of its lack of FLT3 inhibitory activity (Figure 3A‐D,F).